﻿using System;

namespace Program09
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入一个整数");
            int A = Convert.ToInt32(Console.ReadLine());
            int T = 1;

            if (A == 0 || A == 1)
            {
                return;
            }
            else
            {
                for (int i = 1; i <= A; i++)
                {
                    T = T * i;
                }
            }
            Console.WriteLine("1到{1}相乘值为{0}", T, A);

        }
    }
}
